I love that this game is both addicting & chill. I don't have much experience with survival style games but usually they tend to punish on death which is logical. Its awesome that in your game once you die you still can continue the game and how you implemented it (both visual & idea wise) is great. The art is another thing to talk about - it has unique style fits with everything so well. I think you did a really awesome job on the art & design part. Special kudos for making nice progress bar at the top that is both visible and no intrusive, love it. Its usually one of my complaints for games that some elements take too much attention but in your case you managed to keep it clean & simple which is perfect. Another complaint that I usually have in similar games is how the upgrades appear. Sometimes they just immediately pop up, you accidentally click something and then continue. You handled this case perfectly - You have a quick yet smooth transition and you are not allowing player to make a mistake. Instead, you require explicit input (1, 2, 3).
Overall I think you did a really great job on the game and even in this stage it can be enjoyed more than some of the "full release games". I can give much praise for different elements but hope you get the main point :)
P.S. There was one minor bug - Enemy spawned inside the crystal but it was able to get out of it.